PROJECT SUMMARY GENETIC ENGINEERING TECHNOLOGIES The Genetic Engineering Technologies Shared Resource (GET) provides JAX Cancer Center (JAXCC) members with all-inclusive access to the technical expertise, instrumentation, and centralized facilities necessary to engineer and produce complex, precisely tunable, genetically engineered mouse models of cancer. Genetic manipulation of the mouse genome and the production of novel genomic variants has been critical for evaluating gene function in an organismal context. Unfortunately, many strains have been recalcitrant to genetic engineering owing to their reproductive biology constraints and inefficiencies with the methods that induce the gene modification. Thus, to produce next-generation mouse models, these limitations must be overcome by combining optimal genetic background (i.e., strain) with the ability to engineer single, or multiple, genomic variants with high efficiency in a cost-effective manner. Through the integration of molecular construct development, cell biology, microinjection and viral vector expertise, GET is capable of taking a project from conception to delivery of live mice with transient or germline-transmissible engineered mutations. On behalf of the JAXCC members, GET performs the associated genetic engineering approaches, including allele design, gene-editing reagent synthesis and QC, genotyping assay development, and mouse zygote or ES cell gene- editing manipulation with modern targeted nuclease technology (CRISPR/Cas). The group has extensive experience (>1000 CRISPR/Cas gene editing projects) and success generating genetically modified mice on over 100 different inbred and specialty strains, and provides all the necessary husbandry to produce and validate newly engineered mouse models. The design and production of high-titer viral vector preparations enable JAXCC members to create somatic transgenesis mouse models that complement germline mutant models. Staff within all components of GET provide consultation and experimental design support with gene engineering specialists, as well as support for animal care and use, biosafety and biosecurity applications, training, and provision of tested reagents and supplies for those investigators who choose to carry out aspects of the genetic engineering and cell biology processes in their own laboratories. Our Specific Aims are to: 1) Provide a comprehensive, precise genome engineering service capable of generating germline-transmissible alleles not limited by the mouse strain of origin; 2) Provide comprehensive recombinant virus genome engineering tools for introducing precise genetic modifications in mammalian cells; and 3) Provide molecular, cellular or embryological tools for gene engineering or target validation processes for JAXCC members. Execution of these aims in a centralized resource provides a cost effective, scalable, and precise genome engineering platform as well as the technical and operational experience no single research laboratory could effectively create and maintain. This is the value of GET for the JAXCC.